In the past, building structures such as metal buildings or buildings with concrete structural members, or buildings with combinations of concrete and metal structural members have been insulated in many ways. For example, fiber glass blanket insulation has been put between the structural members and held in place with such things as metal straps, chicken wire, etc. Rigid or semi-rigid boards of felted fibers such as fiber glass have also been used for insulating metal and concrete buildings, but no attempt was made to isolate the structural members from the interior of the building and such rigid or semi-rigid boards do not provide sufficient insulation to meet the newly emerging standards.
Another insulating system used extensively, particularly in metal buildings, is shown in FIG. 1 and is described in detail in U.S. applications Ser. Nos. 588,734 and Ser. No. 591,584, both filed in June, 1975 and assigned to Johns-Manville Corporation, assignee of the present application. This insulation product, known in the trade as RIGID-ROLL, comprises a layer of bonded glass fibers A which is flexible, but yet board-like in that it tends to return to a board-like product after being bent and released. The layer of bonded glass fibers is faced with a vapor barrier facing B such as a vinyl facing. The facing, along a longitudinal edge, extends beyond the layer of bonded glass fibers to form a tab (not shown). The tab is reinforced such that when the strips of RIGID-ROLL are butted together so that the tab overlies the adjacent strip, the tab forms a vapor barrier seal between adjacent strips when the metal roof sheets C are fastened against the structural members, or purlins D. While such an insulation system is easy to install and offers many advantages over other systems, compression of the fibrous layer between the outer sheets C and the structural members D seriously reduces the insulating value of the insulation at those areas. As a result, such a system alone will not meet the high insulating standards required by either specifications or by economics for many areas of the country.
The object of the present invention is to provide an insulation system which can be used in new construction or in the reinsulation of old construction, that can be used either alone or in conjunction with prior art insulation systems of the type shown in FIG. 1, and that will provide a more efficient insulation system for the types of buildings described above by insulating and isolating all or most of the structural members of the building from the differing temperatures of the interior and the exterior of the building.